Screw conveyer and the like having interrupted flights



Dec. 22, 1953 H. s. MESSING ,663,40

SCREW CONVEYER AND THE LIKE HAVING INTERRUPTED FLIGHTS Filed Aug. 16, 1951 INVENTOR. Iva/" err Mess-Ina BY ATTORNEY Patented Dec. 22, $953 D: STATES rarest soREw-ooNvEYERAND THE LIK HAVING, V I

v INTERBUPTED'FLIGHIS' 3 Hiah r IS; Mesa; 'N

American Defibrator v i ml e liei ,7 U

V .A'p'plication migus'tis, 1951, Serial Na'zlzis's' '3 claim (9 1 1 9s21 3)f This invention relates to defibrators such as are usually employed forthe production Oflpulp from ligno cellulose materials, such as wood chips, an example ,of. such apparatus being found in the patent to Asplund' No. 2,145,851, datedtiliebruary 7, 1939, and to other devices in which spiral conveyors-may beadvantageously employed. .7 H

In such an apparatusass'hown' in the Asplund patent is employed a sprew qqnygyo; which operates to provide' a-uniform flow of material throughgthe apparatus andasknown at the-press ent time, such conyeyors are usually in the form of a spiralscrew feed hayingin somegcas,e s, a continuous flight, and in other cases interrupted flights. It has been found that with the use of a continuous flight on the conveyor, or event with the employment of uniform-diameter interrupted flights thereon, the preheated chamber in which the conveyor is operative frequently becomes clogged. This especially occurs when the deflbrator is employed for the processing of wood chips, bark, sawdust and other wet, pitchy and ummy materials.

It is therefore an object of the present invention to provide a screw conveyor particularly adapted for use in connection with the above ma terials and in which a marked increase in the filling up of the available space in the preheater will result. It is another object of hte invention to provide an interrupted flight screw which produces a stirring effect on the material; which will relieve pressure on the peripheral portion of the plug of material that is being moved ahead and thi serves to prevent clogging of the pipe and causes the material to fill and preheat the preheating chamber uniformly.

These and other objects are attained by the invention, a more particular description of which will hereinafter appear and be set forth in the claims appended hereto.

In the accompanying drawing, wherein an illustrative embodiment of the invention is disclosed, Fig. 1 is a longitudinal sectional view through a screw conveyor constructed in accordance with the invention;

Fig. 2 is a sectional view taken substantially on the line 22 of Fig. 1, looking in the direction of the arrows, and

Fig. 3 is a sectional view taken substantially on the line 33 of Fig. 1, looking in the direction of the arrows.

In the embodiment shown in the drawing, It indicates a feed chamber of substantially cylindrical form into which the material to be treated gradually increasesrin radius -until rY0rk,' N. .7 w Y rk enters from hopper for- (it ofisupply by meansofthefiiilet' openin feed screw. 'incIudesWthe" rotatable shaft: .1 2- -barz rying the interrupted flightsi' to be described.

.izThe shaft is? rotatablyi SUpDortedTat itS 615 site. ends in r=th'"bearingsl 31-fand "14 which are suitably packed; .to faprvent" points. In the. construction: as" illustrated, n the drawing, and starting at the left end of the structure shown in Fig; 1, one fof the flights atthat end of the shaft 12. is" indicatedfatil. the point 4b," a'djacenttothe shaft maximum andcthen sharplynterminates as indi cated at M. The next flight, or that indicated at 3, begins at shaft l2 as indicated at 3b and then gradually increases in radius but does not reach a radius as great as the maximum radius of the flight 4, and terminates sharply as indicated by the end point 3a. The flight shown at 2, which is next on the shaft I2, begins at the shaft at the point designated at 21) and increases in radius to its maximum, and which corresponds in diameter to the maximum diameter of the flight 4. The flight shown at I corresponds in diameter to that shown at 3, the same starting at the point lb, and then increasing to its maximum diameter, which is less than that of the flights 2 and 4, and then sharply terminating at the point la. The flights thereafter provided along the shaft may be repeats of those described, or the flights may alternate in various ways, to not only best secure a positive and uniform feeding of the material, but to mix or agitate the same while it is being fed.

In operation, the material is delivered into the chamber 19 through the inlet opening II from a suitable source such as from a hopper connected to the inlet l I and from which the material is fed by any positive feed means. As the material enters into the chamber II] it is fed along toward the right by the flights to finally enter between the propelling blades I! on theshaft l2, forcing the material toward and into the outlet [8. The action of directing the material into the outlet S8 is facilitated by the disc l9 mounted on the shaft l2 and which'is provided with projecting pins or fingers 20.

The shaft I2 is rotatably driven from a motor or other power source operative to rotate the shaft by means engaging the extended end portion of the shaft indicated at 2| and located externally of the chamber III.

In the arrangement of the several separate flights mounted on the shaft l2, it is preferred that succeeding flights do not truly follow the pitch of the preceding flight but are ofi-set. It is to be noted that each flight begins as a new screw and increase in radius to its maximum and then abruptly terminates at the beginning of the next flight, and this results in each new flight picking up and forcing the material forwardly through the chamber.

While I have herein shown and described one embodiment of the invention, it is apparent that various modifications may be made without departing from the spirit of thein've'ntion. For example, while I have herein shown the several flights on the shaft arranged'and disposed in a certain sequence, it will be apparent'that the same may be otherwise arranged to secure results possibly found more effective when different types of material is being treated. In addition the chamber, its inlet and outlet openings and other elements may be varied according to the particular apparatus in which the feeder is used. Therefore, since such modifications may be made in the structure described Without departing from the scope thereof, it is'intended that all matter contained in the foregoing specification and shown in the accompanying drawing shall be interpreted merely as illustrative and not in a limiting sense.

What I claim is:

1. In an apparatus of the character described, a chamber, a screw feeder rotatively mounted therein, said feeder including a shaft, a flight thereon of gradually increasing radius to reach a maximum closely conforming to the interior diameter' of the chamber, a second flight on the shaft, said second flight starting of small radius to the shaft, with the flight gradually increasing in diameter to its opposite end, said opposite end terminating on a line extending radially from the shaft, each flight starting adjacent to the end of the flight which preceded it.

3; In an apparatus as provided for in claim 2,

wherein some of 'the'lights are of lesser maximum diameter thanothers, with said flights of lesser diameter being located intermediate of those of the greater diameter.

HJALMAR S. MESSING.

References Cited in the file of this patent UNITE STATES PATENTS Number Name Date 134,706 Schultze Jan. 7, 1873 309,567 Schlickeysen Dec. 23, 1884 702,127 Churchill June 10, 1902 noRErGN PATENTS Number Country Date 9,727 Germany Sept. 30, 1879 82,002 Sweden Nov. 13, 1934 

